This invention relates to a wireless input system for a computer.
This application is related to the Japanese patent application No. 337309/1989 which was filed on Dec. 26, 1989 by the same applicant. The present invention differs from that disclosed in the above-mentioned application in the construction that the position of a pen-type input device is detected by detecting light pulses from the pen-type input device, and other constructions are substantially the same in both inventions. Therefore, the above-mentioned application is disclosed herein for reference.
Conventional input devices for computers, for example, in which icons are clicked or a cursor is moved on the display through graphics software, includes a mouse, a joy stick, a light-pen and others. However, they are all mechanically connected with wires to the bodies of the computers.
Recently, as the production of portable computers has been increased greatly, there have been increasing needs for input devices which can be used in any place. For instance, the mice which are generally used require flat surface conditions wherein the surface is smooth and the balls inside the mice do not slip on that surface. When an operator uses a lap-top computer, he cannot use a mouse. In addition to the inconvenience of carrying a computer having the input device connected by a wire, the input devices have disadvantages that their operations are hindered by obstacles on the desk or the wire becomes entangled since the wire is caused to move as the mouse moves. Furthermore, the other input devices such as joy sticks have substantially the same disadvantages as mentioned above since the input devices are mechanically connected with wires to the computers.
In the meanwhile, character recognition in which characters written on the tablet are recognized and judged to be inputted to the computer are also used instead of the keyboard in order to input information to the computer. However, even in this case, if the input to the computer is made through the wire, such an input device also has the same disadvantage as mentioned above.
As mentioned above, conventional input devices, as represented by a mouse, are limited greatly in their usages, and have a disadvantage that input of characters cannot be made without the keyboard. Furthermore, due to the presence of the wire connected to the computer, operations are troublesome and the wire can become entangled as the mouse moves. In addition, it also has the same disadvantages where input is made through a tablet for character recognition without using the keyboard.